Rare Nephrology News

Disease Profile

Corneal dystrophy and perceptive deafness

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
<1 / 1 000 000

< 331

US Estimated

< 514

Europe Estimated

Age of onset

Neonatal

ICD-10

H18.5

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Congenital corneal dystrophy, progressive sensorineural deafness; Harboyan syndrome; CDPD;

Categories

Congenital and Genetic Diseases; Ear, Nose, and Throat Diseases; Eye diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 1490

Definition
Corneal dystrophy-perceptive deafness (CDPD) or Harboyan syndrome is a degenerative corneal disorder characterized by the association of congenital hereditary endothelial dystrophy (CHED; see this term) with progressive, postlingual sensorineural hearing loss.

Epidemiology
To date, 24 cases from 11 families of various origins (Asian Indian, South American Indian, Sephardi Jewish, Brazilian Portuguese, Dutch, Gypsy, Moroccan and Dominican) have been reported.

Clinical description
The ocular manifestations in CDPD include diffuse bilateral corneal edema occurring with severe corneal clouding, blurred vision, visual loss and nystagmus. They are apparent at birth or within the neonatal period and are indistinguishable from the ocular findings characterizing autosomal recessive CHED (CHED2). Hearing deficit in CDPD is slowly progressive and is typically identified in patients between 10 and 25 years of age. There are no reported cases with prelingual deafness, however, significant hearing loss in children as young as 4 years old has been detected by audiometry, suggesting that hearing may be affected early in the disease course, even at birth.

Etiology
CDPD is caused by mutations in the SLC4A11 gene located at the CHED2 locus on chromosome 20p13-p12, indicating that CHED2 and CDPD are allelic disorders. A total of 62 different SLC4A11 mutations have been reported in 98 families (92 with CHED2 and six with CDPD).

Diagnostic methods
Diagnosis is based on clinical criteria, detailed ophthalmological assessment and audiometry. Molecular confirmation of the clinical diagnosis is feasible.

Differential diagnosis
A variety of genetic, metabolic, developmental and acquired diseases presenting with clouding of the cornea should be considered in the differential diagnosis (Peters anomaly, sclerocornea, limbal dermoids and congenital glaucoma; see these terms). Audiometry must be performed to differentiate CDPD from CHED2. Autosomal recessive types of CHED (CHED2) and CDPD should be carefully distinguished from the less severe autosomal dominant type, CHED1.

Genetic counseling
More than 50% of the reported CDPD cases have been associated with parental consanguinity and all reported cases have been consistent with autosomal recessive transmission.

Management and treatment
The ocular abnormalities in patients with CDPD may be treated with topical hyperosmolar solutions. However, corneal transplantation (penetrating keratoplasty) represents the definitive treatment. Corneal transplantation results in substantial visual gains and has a relatively good surgical prognosis. Audiometric monitoring should be offered to all patients. Hearing aids may be necessary in adolescence.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Corneal dystrophy
0001131
Corneal opacity
0007957
Sensorineural hearing impairment
0000407
Visual impairment
Impaired vision
Loss of eyesight
Poor vision

[ more ]

0000505
30%-79% of people have these symptoms
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance
0000007
Opacification of the corneal stroma
0007759
Pediatric onset
0410280
Reduced visual acuity
Decreased clarity of vision
0007663
Young adult onset
0011462

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Corneal dystrophy and perceptive deafness. Click on the link to view a sample search on this topic.